Ah, the mandatory anti-Microsoft post. Wondered how long it would take.
If you had a grain of intelligence and any idea of how the real world works you'd know that Microsoft actually started late in life in the patent game. The author of the original article wants them to look bad (of course, he sounds like a linux zealot) but he's dead wrong.
The majority of patents Microsoft (yes, I can write their true name in full several times in a row without exploding in a puff of smoke) were btw acquired by purchasing companies that held patents, especially their earlier ones.
If at this stage they're actively pursueing patents in order to prevent other companies from patenting things that Microsoft invented and uses a lot (after all, that's what the patent haters accuse people who take out patents of constantly) that's only good business sense.
So far Microsoft has shown themselves an excellent neighbour and haven't used any of their patents to attack others, only to protect themselves against attack.